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A087011 Number of primes of form 4n+3 between n and 2n (inclusive). 2
0, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 7, 7, 6, 6, 6, 6, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6, 7, 7, 8, 8, 7, 7, 8, 8, 7, 7, 7, 7, 8, 8, 8, 8, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

Erdos proved that between any n > 7 and its double there are always at least two primes, one of form 4n+1 and one of form 4n+3.

REFERENCES

B. Schechter, "My Brain is Open: The Mathematical Journeys of Paul Erdős," Simon & Schuster, New York, 1998, p. 62.

LINKS

Table of n, a(n) for n=1..102.

CROSSREFS

Cf. A035250, A087010, A087012.

Sequence in context: A025885 A198337 A206483 * A294602 A000174 A156268

Adjacent sequences:  A087008 A087009 A087010 * A087012 A087013 A087014

KEYWORD

nonn

AUTHOR

Jason Earls, Jul 30 2003

STATUS

approved

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Last modified May 26 09:27 EDT 2019. Contains 323579 sequences. (Running on oeis4.)